▎ 摘　　要

NOVELTY - A fully degradable plastic film comprises 80-85 pts. wt. polylactic acid, 20-25 pts. wt. corn starch, 25-30 pts. wt. hemp fiber, 0.8-1 pt. wt. KH550 (RTM: ( gamma )-aminopropyltriethoxysilane), 12-14 pts. wt. glycerol, 1.6-2 pts. wt. epichlorohydrin, 1 mol/l sodium hydroxide solution, 1 mol/l hydrochloric acid, distilled water, 2-3 pts. wt. polyethylene glycol, 3-4 pts. wt. montmorillonite, 6-8 pts. wt. oxidized graphene and 1-1.3 pts. wt. vinyltriethoxysilane. USE - Fully degradable plastic film with enhanced barrier properties of graphene oxide, used for preservation bags and food packaging bag. ADVANTAGE - The plastic film has enhanced thermal stability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation method of fully degradable plastic film, which involves dissolving hemp fiber into 1 mol/l sodium hydroxide solution, heating at the atmospheric pressure and at 100 degrees C for 2.5-3 hours, cooling, washing with 1 mol/l hydrochloric acid to neutral, drying in an oven, placing into a pulverizer to be crushed into 200-mesh powder, dissolving KH550 (RTM: ( gamma )-aminopropyltriethoxysilane) in distilled water, forming 1% aqueous solution of KH550 (RTM: ( gamma )-aminopropyltriethoxysilane), crushing into 200 mesh hemp fiber, soaking, heating at 40-50 degrees C, soaking for 40-60 minutes, filtering the precipitate, placing into oven, drying at 90-100 degrees C for 3-4 hours to obtain surface hemp fiber powder, dissolving corn starch in 3 times the amount of distilled water, dripping 1 mol/l solution of sodium hydroxide, stirring until the pH is reached to 9.5, slowly dripping epichlorohydrin in water bath, controlling the water bath temperature to 50 degrees C, stirring for 4-5 hours, adjusting the pH to 6.5 with 1 mol/l hydrochloric acid, leaving still for 30 minutes, discarding supernatant, washing with distilled water, drying into the oven, mixing the surface-treated hemp fiber powder with the dried corn starch, mixing with glycerin, kneading into a kneader at 100-120 degrees C for 30-40 minutes, extruding, ball-milling extruded mixture in a ball mill for 6-8 hours, drying into the oven at 130-140 degrees C to obtain reinforced masterbatch, mixing montmorillonite, graphene oxide and vinyl triethoxysilane into the ball mill, milling for 2-3 hours, adding total amount of 10 times the amount of distilled water, stirring at a rate of 300 rpm to form suspension, adding polyethylene glycol, heating at 40-50 degrees C, stirring for 30 minutes, heating at 80 degrees C, stirring mixture at 1200 rpm for 2 hours, stopping stirring, taking precipitate, washing precipitate three times with distilled water, placing precipitate into a granulator for extrusion granulation, drying into the oven to obtain dried granules, adding polylactic acid to internal mixer, stirring at 150 degrees C for 1 minute, adding reinforced master batch and the dry granules, continuously kneading for 10-12 minutes, carrying out hot melt extrusion blow molding, qualitative-winding and packaging.